fix(material/list): Move unthemable tokens to theme mixin (#27607)

Though these tokens are not currently affected by the theme, in the
future they will be affected by the design system used for theming (M2
or M3)

BREAKING CHANGE:
There are new styles emitted by `mat.list-theme` that are not
emitted by any of: `mat.list-color`, `mat.list-typography`,
`mat.list-density`. If you rely on the partial mixins only and don't
call `mat.list-theme`, you can add `mat.list-base` to get the
missing styles.

Author: amysorto

src/material/_index.scss

@@ -101,7 +101,8 @@
 @forward './icon/icon-theme' as icon-* show icon-theme, icon-color, icon-typography, icon-density;
 @forward './input/input-theme' as input-* show input-theme, input-color, input-typography,
   input-density;
-@forward './list/list-theme' as list-* show list-theme, list-color, list-typography, list-density;
+@forward './list/list-theme' as list-* show list-theme, list-color, list-typography,
+list-density, list-base;
 @forward './menu/menu-theme' as menu-* show menu-theme, menu-color, menu-typography, menu-density;
 @forward './paginator/paginator-theme' as paginator-* show paginator-theme, paginator-color,
   paginator-typography, paginator-density;

src/material/list/_list-theme.scss

@@ -4,13 +4,21 @@
 @use '@material/radio/radio-theme' as mdc-radio-theme;
 @use '@material/list/list-theme' as mdc-list-theme;
 
+@use '../core/style/sass-utils';
 @use '../core/theming/theming';
 @use '../core/tokens/m2/mdc/checkbox' as tokens-mdc-checkbox;
 @use '../core/tokens/m2/mdc/radio' as tokens-mdc-radio;
 @use '../core/tokens/m2/mdc/list' as tokens-mdc-list;
 @use '../core/typography/typography';
 @use '../core/typography/typography-utils';
 
+@mixin base($config-or-theme) {
+  // Add default values for tokens not related to color, typography, or density.
+  @include sass-utils.current-selector-or-root() {
+    @include mdc-list-theme.theme(tokens-mdc-list.get-unthemable-tokens());
+  }
+}
+
 @mixin color($config-or-theme) {
   $config: theming.get-color-config($config-or-theme);
   $primary: map.get($config, primary);
@@ -140,6 +148,7 @@
     $density: theming.get-density-config($theme);
     $typography: theming.get-typography-config($theme);
 
+    @include base($theme);
     @if $color != null {
       @include color($color);
     }

src/material/list/list.scss

@@ -75,11 +75,6 @@
       @include token-utils.create-token-slot(background-color, list-item-leading-avatar-color);
     }
   }
-
-  // Add default values for tokens that aren't outputted by the theming API.
-  .mat-mdc-list-base {
-    @include mdc-list-theme.theme(m2-mdc-list.get-unthemable-tokens());
-  }
 }
 
 a.mdc-list-item--activated {